answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
jekas [21]
2 years ago
14

An object of mass m is dropped from height h above a planet of mass M and radius R.Find an expression for the object's speed as

it hits the ground
Physics
1 answer:
Mnenie [13.5K]2 years ago
4 0

Answer:

Explanation:

Mass of object = m

Height above planet = h

Mass of planet = M

Radius of planet = R

As we have to find out velocity, so let's apply the law of conservation of energies on initial( when the object was at height) and final( when object hit the surface points.

Initial energy = Final energy

K_{i} + U_{i} = K_{f} + U_{f}

\frac{1}{2}mv_{i} ^{2}  - \frac{GMm}{h+R} = \frac{1}{2}mv_{f} ^{2}  - \frac{GMm}{R}\\v_{i} = 0\\v_{f} ^{2} = 2\frac{GM}{R} - 2 \frac{GM}{h+R}

v_{f} =\sqrt{\frac{2GMh}{R(R+h)} }

You might be interested in
Derive an expression for the total mechanical energy of the system as the monkey reaches the top of the motion, Etop, in terms o
ipn [44]

Answer:

U =  0.5 * k *(x + d - h_max)^2 + m*g*h_max

Explanation:

Given:

- The extension in spring @ equilibrium = x m

- The spring constant = k

- The amount of distance pulled down = d

- mass of the toy = m

Find:

- The total mechanical energy E_top at the top position h_max in terms of the available variables.

Solution:

- First we need to determine the types of Energy that are in play:

- The Elastic potential Energy E_p in a spring is given:

                              E_p: 0.5 * k * (ext)

- In our case when the toy at the top most position h_max will have a net extension ext, by summing displacement of spring:

             ext = Equilibrium + distance pulled - h_max = (x + d - h_max)

Hence, the elastic potential energy will be:

                              E_p = 0.5 * k *(x + d - h_max)^2

- The gravitational potential energy E_g is given by:

                              E_g = m*g*h_max

Where, bottom most position is taken as reference (datum).

- The kinetic Energy E_k is given by:

                              E_k = 0.5*m*v_top^2

- Since we know that the maximum height is reached when velocity is zero

Hence,                   E_k = 0.5*m*0^2 = 0.

The total Energy of the system U is sum of all energies and play:

                               U = E_p + E_k + E_g

                               U =  0.5 * k *(x + d - h_max)^2 + m*g*h_max

8 0
2 years ago
Devonte pushes a wheelbarrow with 830 W of power. How much work is required to get the wheelbarrow across the yard in 11 s? Roun
xxMikexx [17]

Answer: 9130 joules

Explanation:

Workdone by wheelbarrow = ?

Time = 11 seconds

Power = 830 watts

Recall that power is the rate of doing work. Thus, power is workdone divided by time taken.

i.e Power = (workdone/time)

830 watts = Workdone / 11 seconds

Workdone = 830 watts x 11 seconds

Workdone = 9130 joules

Thus, 9130 joules of work is required to get the wheelbarrow across the yard.

8 0
2 years ago
Read 2 more answers
Two objects are placed in thermal contact and are allowed to come to equilibrium in isolation. the heat capacity of object a is
Harman [31]
Given:
Ca = 3Cb                      (1)
where
Ca =  heat capacity of object A
Cb =  heat capacity f object B

Also,
Ta = 2Tb                     (2)
where
Ta = initial temperature of object A
Tb = initial temperature of object B.

Let
Tf =  final equilibrium temperature of both objects,
Ma = mass of object A,
Mb = mass of object B.

Assuming that all heat exchange occurs exclusively between the two objects, then energy balance requires that
Ma*Ca*(Ta - Tf) = Mb*Cb*(Tf - Tb)           (3)

Substitute (1) and (2) into (3).
Ma*(3Cb)*(2Tb - Tf) = Mb*Cb*(Tf - Tb)
3(Ma/Mb)*(2Tb - Tf) = Tf - Tb

Define k = Ma/Mb, the ratio f the masses.
Then
3k(2Tb - Tf) = Tf - Tb
Tf(1+3k) = Tb(1+6k)
Tf = [(1+6k)/(1+3k)]*Tb

Answer:
T_{f} =( \frac{1+6k}{1+3k} )T_{b}= \frac{1}{2}( \frac{1+6k}{1+3k})T_{a}
where
k= \frac{M_{a}}{M_{b}} 
7 0
2 years ago
3. What conclusion can you make about the electric field strength between two parallel plates? Explain your answer referencing P
KIM [24]

Answer:

From the relation above we can conclude that the  as the distance between the two plate increases the electric field strength decreases

Explanation:

I cannot  find any attached photo, but we can proceed anyways theoretically.

The electric field strength (E) at any point in an electric field is the force experienced by a unit positive charge (Q) at that point

i.e

E=\frac{F}{Q}

But the force F

F= \frac{kQ1Q2}{r^2}

But the electric field intensity due to a point charge Q at a distance r meters away is given by

E= \frac{\frac{kQ1Q2}{r^2}}{Q} \\\\\E= \frac{Q1}{4\pi er^2 }

<em>From the relation above we can conclude that the  as the distance between the two plate increases the electric field strength decreases</em>

6 0
2 years ago
The acceleration due to gravity for any object, including 1 washer on the string, is always assumed to be m/s2. The mass of 3 wa
Pachacha [2.7K]

Answer:

The force will increase in proportion to the mass of the objects

Explanation:

The acceleration due to gravity is always the same. It is expressed in meters per second squared or m/s². The figure of 9.81 m/s² is an average value that was taken after calculating the acceleration under different surfaces. In fact, the acceleration differs depending on the shape of the part of the earth in relation to the earth's magnetic field and force.

Thus, if one washer was 20 kg, the acceleration being 9.81 m/s² the weight will be:

F = ma

  = 20 * 9.81\\= 196.2 N

If there are there washers, the weight will be:

F = 3 * 20 * 9.81

  = 588.6 N

5 0
2 years ago
Read 2 more answers
Other questions:
  • The heat capacity of an object depends in part on its ____.
    6·1 answer
  • The work of which scientist(s) helped to explain light's ability to propagate through a vacuum? A. Newton B. Davisson and Germer
    6·2 answers
  • a pebble is dropped down a well and hits the water 1.5 seconds later. using the equations for motion with constant acceleration,
    7·2 answers
  • A compact, dense object with a mass of 2.90 kg is attached to a spring and is able to oscillate horizontally with negligible fri
    13·1 answer
  • A burglar drops a bag of loot fr a window hotel. The bag takes 0.15s to pass the 1.6m tall window of your room as it falls towar
    13·1 answer
  • A 5-kg can of paint is sitting on top of a 2-meter high step ladder. How much work did you do to move the can of paint to the to
    10·1 answer
  • Electric field lines always begin at _______ charges (or at infinity) and end at _______ charges (or at infinity). One could als
    5·1 answer
  • A resistor R1 is wired to a battery, then resistor R2 is added in series. Are (a) the potential difference across R1 and (b) the
    6·1 answer
  • The constant pressure molar heat capacity, C_{p,m}C p,m ​ , of nitrogen gas, N_2N 2 ​ , is 29.125\text{ J K}^{-1}\text{ mol}^{-1
    12·1 answer
  • The maximum tension that a 0.80 m string can tolerate is 15 N. A 0.35-kg ball attached to this string is being whirled in a vert
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!